The invention relates to a method for producing a distributed wave winding for electric motors or generators, especially those with a high number of poles.
In simple undistributed wave windings (see European Patent Disclosure EP 0 226 550 B1, FIG. 1), each phase is a single wave-like coil group, which then when inserted in the stator has the same number of windings in the stator slots as in the stator winding heads. This has the disadvantage that when three phases are placed in the stator, crossings are created that unnecessarily enlarge the winding head, and aside from other disadvantages in particular prevent a high fill factor from being attained. For this reason, a so-called distributed winding is as a rule preferred, in which the wire portions located in a slot of the stator are partly in one circumferential direction and partly in the other on each end face of the stator (see German patent disclosure DE 29 21 114, FIG. 2). Thus the winding heads of one phase are distributed, and together with the other identically disposed phases, they form a relatively narrow winding head.
If the wave winding, for instance according to German Patent Disclosures DE 23 51 952 B2 or DE 31 20 865 A1, is prewound essentially in a round form and then deformed into a star-like or wave-shaped cross section and then inserted, then while double-layered wave windings can still be made, nevertheless the two layers cannot be wound in succession without an interruption in the wire; instead, after the insertion, which results in the situation shown in German Patent DE 35 22 085 C2, they have to be joined together by a so-called circuit interconnection.
Finally, from German Patent DE 42 44 488 C1, it is also already known to create concentric wave-like windings by means of a winding nozzle that revolves relative to a fixed template and to make a distributed winding as described, without any interruption in the wire. However, this is feasible only with the aid of a complicated wire length pulling device, not shown in the reference. This is because when a second coil group begins to be wound, it is necessary for the end of the first coil group that has already been ejected to be held using a wire length pulling device.
In this method, aside from the complicated wire length pulling device required, there is the disadvantage that a revolving winding nozzle winds the coils. As a result, at most two parallel winding wires can be processed. This restriction is due to the fact that the revolving winding nozzle is a flyer with multiple deflections of the winding wire.
Particularly for generators, it is necessary to produce a plurality of parallel windings, that is, more than two such parallel windings; thus the known device runs up against its limits, since even with doubly parallel windings, crossings in the flyer and on the template occur that affect the insertion and the distribution in the winding head.
It is therefore the object of the invention to create a method of the type defined at the outset and a device suitable for performing the method, which with a short cycle time make it possible to produce a distributed winding with a circuit interconnection between the coil groups and the processing of a plurality of parallel wires.
The above object is attained according to the invention in that after the transfer of a concentric coil group a relative indexing takes place between a template and a coil receiver, and after that a further concentric coil group of the same phase with a connection to the previous coil group is wound onto the template and transferred into the coil receiver.
The invention offers the advantage that the beginning of winding of the second coil group takes place without a complicated wire length pulling device, since the end of the first coil group after the ejection extends obliquely over one flank of a cam of the template, so that when the second coil group begins to be wound, the winding wire is carried along by the template. In certain cases, especially with relatively thin wires, it is necessary for a holding-down device to restrain the already-wound first coil group in the coil receiver and keep it in position, so that when the second coil group begins to be wound, the winding wire will be drawn not from the coil receiver but only from the wire guide nozzle.
Another advantage is that a plurality of parallel wiresxe2x80x94at present, four parallel wiresxe2x80x94that are required for the stators of generators can be processed without creating crossings between the individual wires, since the individual wires from wire supply barrels are guided directly via a wire guide nozzle onto the template. The invention also makes it possible to process a multiple of the four parallel wires required in the present instance.
The invention is also designed such that one phase can be distributed over more than two coil groups. This can mean that one phase is distributed over six coil groups, for example. In this example, this does lengthen the cycle time, but a better winding head distribution on the stator is achieved. This still changes nothing in the inventive concept that the six coil groups are wound with a circuit interconnection. This is attained in that in the winding of each further coil group, the template and the coil receiver rotate synchronously, and accordingly so do the various wound coil groups that are deposited in the coil receiver. The synchronous rotation is effected by means of a slaving rod that comes from the middle of the template and is coupled into the insertion star and set jointly into rotation by a template drive.